don't use BT as an ISP No! That's what they want you to do. Because then it means they get to care even less. It's still their infrastructure and therefore

don't use BT as an ISP No! That's what they want you to do. Because then it means they get to care even less. It's still their infrastructure and therefore their van that needs to come out to your house to fix things, but you've added yet another layer onto the process. They've worked their contracts with the ISPs so that the ISP can't actually do anything in your name, so you still end up on the phone with them, but you're not their customer so you can't mention anything being wrong with the internet as clearly that's your ISP's problem. No, now "the phone line is really scratchy" is your only line of attack and god help you if you've contracted that out to a 3rd party (or worse, your ISP itself!) Then they've cleverly broken off the van that comes to fix things (BT OpenReach) as a separate company that you can't talk to, so you have to go through BT's call center, which will helpfully tell you that there's no fault, and that it will cost $150 to send a van out if it turns out they can't find anything (d'ya feel lucky, punk?). Fortunately, the van guys are actually good. And BT's infrastructure is so terrible that there's always at least one fault they can find. Usually about 5 meters further down the line than last time they were had the truck out two weeks ago. One day somebody will lay some fiber that has no BT-ness associated with it at all. And they'll get everybody's business.